Flexible package for hydrocolloid impression materials



Jan. 18, 1938. w. J. IAN ROSSEM 2,105,623

FLEXIBLE PACKAGE FUR HYDROCOLLOID IMPRESSION MATERIALS Filed Jul y 26, 1937 'INVENTOR. WMRM Hawk/41. 4 aw!!! ATTORNEYS package.

atented Jan. 18, 1938 ATES OFFICE FLELE PACKAGE ron mmnocouom IMPRESSION MATERIALS Application July 26, 1937; Serial No. 155,721

8 Claims.

This invention relates to an advantageous packagein which a plastic moisture-containing imdrocolloid' or other moisture-containing material without loss of moistureiior an indefinite period.

A further important object of the invention is to provide a package of the character described which will preserve a moisture-containing material against-moisture loss in storage and which will be resilient and capable of elastic deformation, without losing its ability to preserve the moisture-containing material, at temperatures 2% adjacent or in the'neighborhood of the boiling point of water.

A particular object of the invention is to provide a package of the type described, having a projecting thread-like member embedded in the hydrocolloid or other moisture-containing material, to aid in the formation of the package and in subsequent handling thereof.

The package of the present invention is primarily adapted for enclosing dental impression materials or compositions having a moisture-contalning reversible hydrocolloid base. These materials are in general semi-rigid when cool and must be heated to render the same fluent for use. Compositions of this general type are described in U. S. Patent No. 1,672,776-and in the two U. S. patents to Laurence E. Harrison, Nos. 2,021,058 and 2,020,311. p The package of this invention comprises in general, a body of moisture-containing hydro- 40 colloid material which is adapted to become plastic upon heating, enclosed by an envelope of moisture impervious material. A threadlike member is secured to the package and extends outwardly thereof to facilitate handling of the -The term thread-like member is meant to include a wire, a fabric thread, or any other suitable thread-like member, as will be apparent as the description proceeds. I prefer to utilize a substantially continuous moisture-impervious envelope coating for a body of such impression material which adequately protects the material from contamination and preserves the moisture content of the material, such envelope coating being of a material which is of high mechanical strength at ordinary temperatures but of 35 to 40 C., as it is common practice in dental readily capable of elastic deformation at elevated temperatures whereby the packages may be immersed in water and heated to render the contained material fluent after which the package may be kneaded, if desired, to homogenize the material and render the same suitable for use, without danger of rupture during the kneading operation.

Further objects and advantages of the invention will either be specifically brought out in the 10 following description or will be apparent therefrom. 1 I have illustrated packages embodying my invention in the accompanying drawing, and referring thereto: 15

Fig. 1- is a side elevation of a body of material surrounded with an envelope of moisture impervious material and provided with a threadlike member; the envelope is shown in sectional elevation and aportion of the body of material 20 at the upper end thereof has been broken away to show the attachment of the thread-like member to the body of material;

Fig. 2 is a perspective view thereof; 7

Fig. 3 is a view corresponding to Fig. 1, showing 25 a modified type of thread-like member; and

Fig. 4 is a side elevation of a further modified form of package.

The coating material is preferably one which, even at the elevated temperatures at which the 30 contained impression material is handled to render the same fluent, retains a high degree of mechanical strength, and preferably also remains substantially moisture-impervious. The coating material is also preferably one having a rela- 35 tively high mechanical strength at ordinary temperatures, a melting point somewhat in excess of C. and relatively resilient and capable of elastic deformation at temperatures in the neighborhood of 100 C. The ability of the material to 40 elastically deform at the high temperatures should persist to an important degree during 0001- ing 'from adjacent 100 C. to in the neighborhood technique to continue the kneading of the heated 5 composition until the; temperature thereof has dropped to a point such that it may be inserted within the mouth of a patient without undue discomfort. Numerous compositions are available, 50 for the fabrication of this envelope, such as the vinyl resins, among which may be listed the commercially available Koroseal which has'a melting point slightly below C., or combination solutions of cellulosic compounds and a moisture- 55 proofing material such as rubber, resins, resinous gums, and high melting point waxes.

As a specific example. of a coating material which may be employed, I may take two separate equal volumes of hexalin (hexa-hydro-phenol), dissolve from 10 to 30% by weight of celluloid in one of the volumes and from 10 to 80%by weight of raw rubber in the other of said volumes, and then intermix the two volumes to form a composite solution which may, if desired, be evaporated to a honey-like consistency.

Alternatively, an unloaded vulcanized rubber may be incorporated in the coating material, in which case I preferably employ a solvent such as hexalin acetate (cyclohexanol acetate), which provides somewhat better intersolution of celluloid and vulcanized rubber than does the alcohol hexalin itself. Substantially the same proportions may be employed as are above set forth, and the solutions may be more rapidly prepared by heating (preferably to a temperature below the flash-point of the solvent if carried out in the open, or to a higher temperature under reflux condensationl.

Any of the above materials, such as Koroseal, for example, may be used to form a continuous envelope for the abovedescrlbed moisture-containing hydrocolloid impression compound, as by forming a cylindrical or other suitably shaped body of such hydrocolloid compound by extrusion, molding or the like, inserting a thread-like memher into one end of the cylinder and then dip ping the cylinder into one of the above described solutions, withdrawing the dipped cylinder and allowing the coating to dry. 7

Thus in'Fig. 1 a body of hydrocolloid material is indicated at I and provided with a thread-like member 2 such as a fine wire or fabric thread which has been knotted or otherwise provided with an enlarged portion 3 and inserted in one end of the stick of material I. The stick of material may be carried by the member 2 and dipped into a bath of envelope material such as Koroseal to form an envelope coating indicated at 4. The completed package is shown in perspective in Fig. 2.

- pings in this manner and the thread-like member will be secured to the envelope by the natural shrinkage of the envelope material and the package will be substantially moisture impervious.

I prefer, however, to form the package by a double dipping procedure, as by holding the stick I by the thread-like member 2 and immersing it somewhat over one-half its length, allowing the coating to congeal and then inverting the stick and dipping the end to which the thread-like member is attached, so that the two coatings overlap to form a moisture impervious envelope. When a fabric thread or a very fine wire is used as the thread-like member it is diflicult to obtain the second dip since the thread is dlfllcult to submerge due to its flexibility and also because it is liable to become attached to the side of the envelope.

To overcome these disadvantages when the double-dipping procedure is followed, I prefer to use a relatively stlfl wire for th'e thread-like memher. Referring to Fig. 3, the body I is shown provided with a thread-like member 6, such as a relatively stiff wire, having an end 1, formed as a corkscrew or otherwise enlarged, secured to the body I. A loop 8 may be advantageously formed in the other end of the wire or thread-like member to' facilitate handling thereof so that the packages may be hung on a peg or so that other threads may be attached thereto. The package is shown dipped so that the envelope material completely surrounds the thread-like member as at e. A further modified form of package is illustrated in Fig. 4 in which a stick of material indicated at I I may be grasped by one end and dipped to form a partial coating for a length such as indicated by the bracket l2. A thread-like member l3 such as a wire or fabric cord may then be held against the coated portion l2 and allowed to lie against the uncoated portion of the stick as at H. Phe stick may then be clipped to form a coating extending for the length indicated by the bracket IS. The coating l5 covers the lower dotted portion of the thread-like member is and secures said member to the envelope in the portion of the envelope where the coatings I 2 and vantageous to pre-dip the thread-like members before using them in the fabrication of the package. It should also be noted that the thread-like member may be attached to the outside of the package, in which case it does not extend into the envelope, without departing from the spirit of this invention. Furthermore, it will be appreciated that a plurality of thread-like members may be provided, which may, if desired, be interlaced and used to support the hydrocolloid stick during the dipping operation, and contributing to some degree to the strength of the packagecoating.

It will also be appreciated that the thread-like member may be considered to extend through the envelope which covers the stick of material in Figs. 1-4, even though an additional coating of envelope material is shown at 9 on the member 6 in Fig. 3. Where an absorbent thread-like member is employed, the coating material will penetrate the body of the member, effecting a seal against capillary loss of moisture through the member.

The portion of the string or wire which remains within the body of the material will present no difliculty in the subsequent use of the material inasmuch as such material is rendered fluent by immersion in a heated fluid such as water and subsequently extruded from the package after slitting or cutting the same at one end. The thread-like member attached to the package facilitates subsequent handling thereof during the heating operation which is carried out to render the contained material fluent. For example, if the string or wire is of such length as to extend 8 to 12 inches from the package, it may though it projects from the package for sure is concerned are fairly conductive electrically, due to the presence of sodium sulphate, alum or the like, the wire 6 may be used to supply an anodic deposit from a colloidal rubber dispersion to produce a rubber coating thereon.

I do not choose to be limited to the specific coating materials herein set forth in the preparation of the envelope of the present invention, as there are numerous other coating materials which will provide the described moisture-retentive envelope having the property of being elastically deformable at temperatures adjacent to or in the neighborhood of the boiling point of water and which will give the desired seal between the thread-like member and the envelope to prevent undue moisture loss.

I claim:

1. A moisture-impervious package comprising a body of moisture-containing hydrocolloid material adapted to become plastic upon heating, an enclosing envelope of moisture-impervious material surrounding said body, and a threadlike member secured to said package and extending therefrom to facilitate handling -of such package.

2. A moisture-impervious package comprising a body of moisture-containing hydrocolloid material adapted to become plastic upon heating, an enclosing envelope'of moisture-impervious material surrounding said body, and a thread-like member secured to said body and extending through said envelope to facilitate handling of such package.

3. A package as set forth in claim 2, said thread-like member also being secured to said 4. A package as set forth in claim 2, said thread-Like member being secured to said envelope and forming a substantially moisture-impera thread-like member secured. to said body and,

extending outwardly thereof for facilitating the handling of said package, and an envelope of moisture-impervious material surrounding said body and in engagement with said thread-like member to provide a moisture-impervious enclosure for said body. I

7. The package set forth in claim 6, said thread-like member comprising a thin metallic wire.

8. A moisture-impervious package comprising a body of moisture-containing hydrocolloid ma-,

terial adapted to become plastic upon heating, a plurality of thread-like members engaging said body and at least one of said members extending outwardly thereof for facilitating the handling of said package, and an envelope of moisture-imper-, 

